Grammar, страница 99 - гдз по английскому языку 9 класс учебник Комарова, Ларионова

Unit 7. Against the odds. Language guide - страница 99.

Условие.

Grammar

Modals of obligation, prohibition and ability

obligation and prohibition (present)

• There is usually no difference in meaning between must and have to. However, we tend to use must when we give our personal feelings and have to for facts.

• We use don't have to when there is no obligation (something isn't necessary). Sometimes Alain is invited to do a stunt, so he doesn't always have to avoid the police.

• We use mustn't when something is prohibited. It doesn't have the same meaning as don't have to.

  • You mustn't use this lift. (It's prohibited - maybe it doesn't work and it's dangerous.)

  • You don't have to use this lift. (It's not necessary - there are other lifts, or you can walk up the stairs.)

• After must we use the infinitive without to.

  • You must wait here. ✓

  • You must to wait here. ✗

• We use has to in the third person and do/does in questions and the negative.

affirmative (obligation)

I / You / We / They	have to / must	check.
He / She / It	has to / must

negative (no obligation)

I / You / We / They	don't have to	pay.
He / She / It	doesn't have to

negative (prohibition)

I / You / We / They	mustn't	climb.
He / She / It	mustn't

ability (present)

• We use can for ability.

  • Alain Robert can climb the world's tallest skyscrapers.

  • He can't rest until he reaches the top.

• After can we use the infinitive without to.

  • He can climb buildings without ropes. ✓

  • He can to climb buildings without ropes. ✗

obligation (past)

• We use had to in the past. We never use must in the past.

  • We had to tell the security guard. ✓

  • We musted tell the security guard. ✗

• We use didn't have to for no obligation in the past.

  • He didn't have to go to prison - he had to pay a large fine.

ability (past)

• We use could for ability in the past.

  • He could climb mountains without ropes.

  • She couldn't swim when she was six.

Modals of deduction and possibility

• We use must and can't for deduction.

• We use must when we are certain about something because there is a logical explanation for it.

  • Sandra has won the competition. She must be happy.

• We use can't when we are certain that something is impossible.

  • You're making a lot of mistakes. You can't be paying attention.

• We use may or might if we think something is possible, but we aren't certain.

  • He finds it difficult to read and write. He might be dyslexic.

Grammar bank → Workbook p110

Решение 1.

Решение 2.